winsock编程学习1

WSA prefix

WSAStarup()

WSACleanup()

WSARecvEx()

WSAGetLastError()

How to Add Winsock link library WS2_32.lib to the Visual C++ project?

enter :Visual .NET doc 1 and Visual .NET doc 2 articles

Initializing Winsock

int WSAStarup( WORD wVersionRequested, LPWSADATA lpWSAData );

typedef struct WSAData

{

WORD wVersion;

WORD wHighVersion;

char szDescription[WSADESCRIPTION_LEN+1];

char szSystemStatus[WSASYS_STATUS_LEN+1];

unsigned short iMaxSockets;

unsigned short iMaxUdpDg;

char FAR *lpVendorInfo;

} WSADATA,*LPWSADATA;

To find the maximum number of concurrent sockets,you should query the protocol information through WSAEnumProtocols()

int WSACleanup(void)

Error Checking and Handling

int WSAGetLastError(void)

code:

#include<stdio.h>
#include <winsock2.h>
#include <mswsock.h>
int main(void)
{
    WSADATA wsaData;
    int RetCode;
    //initialize Winsock version 2.2
    if((RetCode=WSAStartup(MAKEWORD(2,2),&wsaData))!=0)
    {
        printf( "WSAStartup failed with error %d\n",RetCode);
        return 1;
    }
    else
    {
        printf("The Winsock dll found!\n");
        printf("The current status is:%s.n",wsaData.szSystemStatus);
    }
    if (LOBYTE(wsaData.wVersion)!=2||HIBYTE(wsaData.wVersion)!=2)
    {
        //tell the user that we could not find a usable WinSock DLL
        printf("The dll do not support the Winsock version %u.%u!\n",
            LOBYTE(wsaData.wVersion),HIBYTE(wsaData.wVersion));
        //when your application is finished call WSACLeanup
        WSACleanup();

        //and exit
        return 0;
    }
    else
    {
        printf("The dll supports the Winsock version %u.%u!\n",LOBYTE(wsaData.wVersion),
         HIBYTE(wsaData.wVersion));
        printf("The highest version this dll can support:%u.%u\n",LOBYTE(wsaData.wHighVersion),HIBYTE(wsaData.wHighVersion));
        //When your application is finished call WSACleanup
        if(WSACleanup()==SOCKET_ERROR)
            printf("WSACleanup failed with error%d\n",WSAGetLastError());
        //and exit
        return 1;
    }
}

编译时候,出现一些错误是因为写错,

程序执行结果:

Well,after completing this exercise ,you should be familiar with the steps to create an empty Win32 console application project.

Those steps will be repeated fot almost all the Winsock2 projects in this tutorial .

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1 Tutorials on 'Advanced' Winsock 2 Network Programming

2 C and Winsock2 Topics

3 net-gold

4 VC中Socket初始化以及释放,WSAStartup函数,WSACleanup函数

5 VC++网络编程

6 c++ 初识winsock 基本操作---创建

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